scholarly journals Fate of nitrogen (15N) from velvet bean in the soil-plant system

2004 ◽  
Vol 61 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Walkyria Bueno Scivittaro ◽  
Takashi Muraoka ◽  
Antonio Enedi Boaretto ◽  
Paulo César Ocheuze Trivelin
Keyword(s):  
Incubation Period ◽  
Green Manure ◽  
Plant Material ◽  
Rice Cultivation ◽  
Isotopic Dilution ◽  
Velvet Bean ◽  
Plant System ◽  
Rice Plants ◽  
Incubation Periods ◽  
Fate Of Nitrogen

Because of their potential for N2 biological fixation, legumes are an alternative source of nitrogen to crops, and can even replace or supplement mineral fertilization. A greenhouse experiment was carried out to evaluate temporal patterns of velvet bean (Mucuna aterrima) green manure release of nitrogen to rice plants, and to study the fate of nitrogen from velvet bean in rice cultivation. The isotopic dilution methodology was used. Treatments consisted of a control and 10 incubation periods of soil fertilized with 15N-labeled velvet bean (0, 20, 40, 60, 90, 120, 150, 180, 210, and 240 days). The plant material was previously chopped, sifted (10 mm mesh sieve) and oven-dried (65ºC). Incubation of the plant material (2.2 g kg-1 soil) was initiated by the longest period, in order to synchronize the planting of the test crop, rice (Oryza sativa), at time zero for all treatments. Green manure incorporation promoted increases in rice dry matter yield and nitrogen uptake. These variables showed maximum values at incubation periods of 38 and 169 days, respectively. Green manure nitrogen utilization by rice plants was highest at an incubation period corresponding to 151 days. More than 60% of the green manure nitrogen remained in the soil after rice cultivation. The highest green manure nitrogen recovery from the soil-plant system occurred at an incubation period equivalent to 77 days.

scholarly journals ANALYSIS OF LEGOWO ROW PLANTING SYSTEM AND SYSTEM OF RICE INTENSIFICATION (SRI) OF PADDY FIELD (ORYZA SATIVA L.) TOWARD GROWTH AND PRODUCTION

2016 ◽  
Vol 1 (1) ◽  
pp. 14-18 ◽  
Author(s):  
M. Darmawan
Keyword(s):  
Oryza Sativa L ◽  
Block Design ◽  
Treatment Plant ◽  
Cropping System ◽  
Rice Cultivation ◽  
System Of Rice Intensification ◽  
Plant System ◽  
Rice Plants ◽  
Planting Distance ◽  
Planting System

Rice is the main commodity crops in the province of Gorontalo, in addition to maize and pulses. One alternative technology to increase productivity is through application of Legowo cropping system that is engineered way of planting the tiles so that there is a spacious room extends to one direction between two rows of rice plants, while the other way seemed more tightly. In rice cultivation with system of transplanting, planting distance is one factor of production that is very important because it determines the productivity achieved. This research is expected to be a reference for farmers, especially in the province of Gorontalo to carry rice cultivation so as to increase the production of rice plants. The design of the study is a Randomized Complete Block Design by comparing between systems that are often used by farmers, namely row planting system tiles (S0), the system of row planting Legowo (2: 1) (S1), system of row planting Legowo (4: 1 ) (S2), planting system SRI (S3). The parameters of observations made were plant height, number of tillers, production (kg/plot), and observations of soil samplesman. The results showed treatment plant system of tiles provide number of tiller and height of plants that are best compared with other treatments. The best results for a number of productive tillers, the average production of grain/plot, grain weight of 1000 grain was in the treatment plant system Legowo row 2: 1.

Natural maize phytochemicals for control of maize mycoflora and aflatoxigenic fungi

2009 ◽  
Vol 2 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. Nesci ◽  
S. Marín ◽  
M. Etcheverry ◽  
V. Sanchis
Keyword(s):  
Ferulic Acid ◽  
Incubation Period ◽  
Cinnamic Acid ◽  
Inhibitory Effect ◽  
Aspergillus Section Flavi ◽  
Aflatoxigenic Fungi ◽  
Incubation Periods ◽  
Maize Grain ◽  
Aflatoxin B ◽  
Aspergillus Section

This research was undertaken to evaluate the effects of the natural phytochemicals trans-cinnamic acid (CA) alone at concentrations of 20 and 25 mM, ferulic acid (FA) at concentration of 30 mM and two mixtures, CA-FA (20+30 mM) and CA-FA (25+30 mM) on natural maize mycoflora, Aspergillus section Flavi population and aflatoxin B1 production. These studies were carried out in maize grain in relation to a water activity of 0.99, 0.97 and 0.94. CA at 25 mM and the mixture CA-FA (25+30 mM) were the most effective treatments at inhibiting natural maize mycoflora at all aw assayed after 11 and 35 days of incubation at 25 °C. In general, 20 mM CA caused complete inhibition of Aspergillus section Flavi population at all aw values tested during all incubation period without an additional inoculum. 20 mM CA and 25 mM CA showed the major inhibitory effect on aflatoxin B1 accumulation of control and Aspergillus section Flavi additionally inoculated during all incubation periods. The data showed that CA and FA could be considered as effective fungitoxicants for natural maize mycoflora and aflatoxigenic fungi in the aw range 0.99 to 0.94. The information obtained shows promise for controlling aflatoxigenic fungi in stored maize.

scholarly journals Effect of Sucrose Concentrations and Incubation Periods on in Vitro Rooting of Moris Pineapple (Ananas comosus)

2019 ◽  
Vol 34 (4) ◽  
pp. 230-242
Author(s):  
Abdelhamid M Hamad
Keyword(s):  
Incubation Period ◽  
In Vitro Rooting ◽  
Ananas Comosus ◽  
Ms Medium ◽  
Incubation Periods ◽  
Half Strength

The effect of 6 sucrose concentrations (5, 10, 15, 20, 25, 30 g/l) over 4 incubation periods (30, 45, 60, 75 days) on in vitro rooting of Moris pineapple cultured in liquid half strength MS medium enriched with IBA at 2.0 mg/l was investigated. At all incubation periods, all shoots in medium enriched with sucrose at 5 g/l failed to root, and no roots formed within the first 30 days in medium enriched with sucrose at 10 g/l. After 30 days of incubation, the highest rooting percentage (66 %), tallest plantlets (23 mm tall), highest (3.4 roots) and longest (5.3 mm) root per shoot were obtained in medium enriched with sucrose at 25, 10, 15, 15 g/l respectively, while after 45 days, the highest of all rooting aspects (75 %, 32.3 mm tall, 3.7 roots, 7 mm long), were obtained in medium enriched with sucrose at 15 g/l. After 60 days, the highest rooting percentage (91.7 %) and tallest plantlets (36.7 mm tall) were obtained in medium enriched with sucrose at 20 g/l while highest roots per shoot (3.7 roots) and longest root (10.7 mm) were obtained in medium enriched with sucrose at 15 g/l. After 75 days, all shoots rooted (100 %) in medium enriched with sucrose at 10 and 20 g/l, while sucrose at 25 g/l resulted in tallest plantlets (46.3 mm tall) and at 20 g/l resulted in highest (4.7 roots) and longest roots (27.3 mm). At each incubation period, there was a different optimum sucrose enrichment for different rooting parameters.

scholarly journals Estimation of incubation period and serial interval of COVID-19: analysis of 178 cases and 131 transmission chains in Hubei province, China

2020 ◽  
Vol 148 ◽  
Author(s):  
Lin Yang ◽  
Jingyi Dai ◽  
Jun Zhao ◽  
Yunfu Wang ◽  
Pingji Deng ◽  
...  
Keyword(s):  
Incubation Period ◽  
Failure Time ◽  
Age Groups ◽  
Hubei Province ◽  
Interval Censoring ◽  
Contact Tracing ◽  
Considerable Proportion ◽  
Outbreak Period ◽  
Serial Interval ◽  
Incubation Periods

Abstract A novel coronavirus disease, designated as COVID-19, has become a pandemic worldwide. This study aims to estimate the incubation period and serial interval of COVID-19. We collected contact tracing data in a municipality in Hubei province during a full outbreak period. The date of infection and infector–infectee pairs were inferred from the history of travel in Wuhan or exposed to confirmed cases. The incubation periods and serial intervals were estimated using parametric accelerated failure time models, accounting for interval censoring of the exposures. Our estimated median incubation period of COVID-19 is 5.4 days (bootstrapped 95% confidence interval (CI) 4.8–6.0), and the 2.5th and 97.5th percentiles are 1 and 15 days, respectively; while the estimated serial interval of COVID-19 falls within the range of −4 to 13 days with 95% confidence and has a median of 4.6 days (95% CI 3.7–5.5). Ninety-five per cent of symptomatic cases showed symptoms by 13.7 days (95% CI 12.5–14.9). The incubation periods and serial intervals were not significantly different between male and female, and among age groups. Our results suggest a considerable proportion of secondary transmission occurred prior to symptom onset. And the current practice of 14-day quarantine period in many regions is reasonable.

scholarly journals Incubation periods of enteric illnesses in foodborne outbreaks, United States, 1998–2013

2019 ◽  
Vol 147 ◽  
Author(s):  
S. J. Chai ◽  
W. Gu ◽  
K. A. O'Connor ◽  
L. C. Richardson ◽  
R. V. Tauxe
Keyword(s):  
United States ◽  
Incubation Period ◽  
Disease Outbreaks ◽  
Disease Outbreak ◽  
Outbreak Investigation ◽  
Foodborne Disease ◽  
Case Definitions ◽  
Viral Pathogens ◽  
Incubation Periods ◽  
Foodborne Outbreaks

Abstract Early in a foodborne disease outbreak investigation, illness incubation periods can help focus case interviews, case definitions, clinical and environmental evaluations and predict an aetiology. Data describing incubation periods are limited. We examined foodborne disease outbreaks from laboratory-confirmed, single aetiology, enteric bacterial and viral pathogens reported to United States foodborne disease outbreak surveillance from 1998–2013. We grouped pathogens by clinical presentation and analysed the reported median incubation period among all illnesses from the implicated pathogen for each outbreak as the outbreak incubation period. Outbreaks from preformed bacterial toxins (Staphylococcus aureus, Bacillus cereus and Clostridium perfringens) had the shortest outbreak incubation periods (4–10 h medians), distinct from that of Vibrio parahaemolyticus (17 h median). Norovirus, salmonella and shigella had longer but similar outbreak incubation periods (32–45 h medians); campylobacter and Shiga toxin-producing Escherichia coli had the longest among bacteria (62–87 h medians); hepatitis A had the longest overall (672 h median). Our results can help guide diagnostic and investigative strategies early in an outbreak investigation to suggest or rule out specific etiologies or, when the pathogen is known, the likely timeframe for exposure. They also point to possible differences in pathogenesis among pathogens causing broadly similar syndromes.

scholarly journals Egg Size, Eggshell Porosity, and Incubation Period in the Marine Bird Family Alcidae

The Auk ◽  
2007 ◽  
Vol 124 (1) ◽  
pp. 307-315
Author(s):  
Karen Zimmermann ◽  
J. Mark Hipfner
Keyword(s):  
Incubation Period ◽  
Egg Size ◽  
Interspecific Variation ◽  
Egg Mass ◽  
Proximate Mechanisms ◽  
Diffusion Limited ◽  
Evolutionary Changes ◽  
Incubation Periods ◽  
Avian Incubation ◽  
Embryonic Metabolism

Abstract Although the ultimate factors that influence the duration of avian incubation periods are well known, we know much less about the proximate mechanisms by which birds adjust incubation period in response to selection. We tested the hypothesis that an adjustment in eggshell porosity is one such proximate mechanism (i.e., that avian species with higher ratios of incubation period to egg size lay eggs with less porous shells). Eggshell porosity affects the rate of gaseous exchange between the developing embryo and the external environment; thus, to the extent that embryonic metabolism is diffusion-limited, eggshell porosity could directly determine incubation period. To test that hypothesis, we collected eggs from seven species of Alcidae, a family of marine birds that exhibits an unusual degree of interspecific variation in incubation period, and measured egg mass and eggshell porosity (determined by the number and size of pores and the thickness of the shell). Incubation periods were obtained from the literature. Egg mass and eggshell porosity combined explained 87% of the variation in incubation period among the seven species, which included at least one member of each of the six main alcid lineages. As predicted, eggshell porosity and incubation period were negatively related, after controlling for egg mass. Our results are consistent with the hypothesis that evolutionary changes in avian incubation period may be attributed, at least in part, to adjustments in eggshell porosity. Taille de l’Œuf, Porosité de la Coquille et Période d’Incubation chez les Oiseaux Marins de la Famille des Alcidés

scholarly journals Incubation period for outbreak-associated, non-typhoidal salmonellosis cases, Minnesota, 2000–2015

2018 ◽  
Vol 146 (4) ◽  
pp. 423-429 ◽  
Author(s):  
D. Eikmeier ◽  
C. Medus ◽  
K. Smith
Keyword(s):  
Incubation Period ◽  
Period Length ◽  
Accurate Description ◽  
Vehicle Type ◽  
Day Range ◽  
Incubation Periods

AbstractIncubation period for non-typhoidal Salmonella (NTS) infections is generally reported as 6–72 h despite numerous reports of foodborne NTS outbreaks with median incubation periods >3 days. We summarised 16 years of Minnesota foodborne NTS outbreaks to better estimate the expected range of incubation periods for NTS infections. Of the 1517 NTS outbreak cases, 725 had enough data to calculate a precise incubation period. The median incubation period was 45 h; 77 (11%) cases had incubations ⩽12 h and 211 (29%) cases had incubations >72 h. Incubation period length varied by outbreak vehicle type, Salmonella serotype and outbreak setting. Based on our data, a more accurate description would be that the incubation of NTS infection is usually from 12 to 96 h, that incubations in >96 to 144 h (>4 to 6-day) range are not unusual and that incubations from 7 to 9 days and occasionally longer also occur.

scholarly journals Association between incubation period and clinical characteristics of patients with COVID-19

2020 ◽  
Vol 48 (9) ◽  
pp. 030006052095683
Author(s):  
Yeyu Cai ◽  
Jiayi Liu ◽  
Haitao Yang ◽  
Mian Wang ◽  
Qingping Guo ◽  
...  
Keyword(s):  
Incubation Period ◽  
Disease Severity ◽  
Symptom Onset ◽  
Clinical Characteristics ◽  
Characteristic Curve ◽  
Severe Disease ◽  
Receiver Operator Characteristic Curve ◽  
Hunan Province ◽  
Laboratory Findings ◽  
Incubation Periods

Purpose To investigate associations between the clinical characteristics and incubation periods of patients infected with coronavirus disease 2019 (COVID-19) in Wuhan, China. Methods Complete clinical and epidemiological data from 149 patients with COVID-19 at a hospital in Hunan Province, China, were collected and retrospectively analyzed. Results Analysis of the distribution and receiver operator characteristic curve of incubation periods showed that 7 days was the optimal cut-off value to assess differences in disease severity between groups. Patients with shorter (≤7 days) incubation periods (n = 79) had more severe disease, longer durations of hospitalization, longer times from symptom onset to discharge, more abnormal laboratory findings, and more severe radiological findings than patients with longer (>7 days) incubation periods. Regression and correlation analyses also showed that a shorter incubation period was associated with longer times from symptom onset to discharge. Conclusion The associations between the incubation periods and clinical characteristics of COVID-19 patients suggest that the incubation period may be a useful marker of disease severity and prognosis.

scholarly journals Effect of heavy metals on soil respiration during decomposition of sugarcane (Saccharum officinarum L.) trash in different soils

2010 ◽  
Vol 56 (No. 2) ◽  
pp. 76-81 ◽  
Author(s):  
R.K. Verma ◽  
D.V. Yadav ◽  
C.P. Singh ◽  
A. Suman ◽  
A. Gaur
Keyword(s):  
Heavy Metals ◽  
Soil Respiration ◽  
Incubation Period ◽  
Crop Residue ◽  
Sandy Loam ◽  
Saccharum Officinarum ◽  
Sugarcane Research ◽  
Incubation Periods ◽  
Farm Crop ◽  
Different Soils

An experiment was conducted to study the effect of heavy metals (Cd, Cr and Pb), soil texture (sandy, loam and clay) and incubation periods (7, 15, 30, 60, 90 and 120 days) on soil respiration (CO<sub>2</sub> evolution) during sugarcane trash decomposition in laboratory conditions of the Indian Institute of Sugarcane Research, Lucknow, India. Surface soils (0–15 cm) were collected from agricultural fields and crop residue of sugarcane trash (<i>Saccharum officinarum</i> L.) was taken in the institute farm. Crop residue (10 t/ha) and heavy metals (10, 50, 100, 1000 &mu;g/g) were mixed and incubated at 30°C ± 2°C in an incubator. The rate of soil respiration (CO<sub>2</sub> evolution) decreased with increasing heavy metals concentration. During the 120 days, the toxicity decreased but still remained significant. Maximum soil respiration was recorded at 7 days of incubation period; further, it decreased with increasing incubation period. The highest drop of soil respiration rate was caused by addition of 1000 &mu;g/g Cd, Cr and Pb levels. Clay soils evolved maximum CO<sub>2</sub> followed by loam and sandy soil.

scholarly journals Incubation periods impact the spatial predictability of cholera and Ebola outbreaks in Sierra Leone

2020 ◽  
Vol 117 (9) ◽  
pp. 5067-5073 ◽  
Author(s):  
Rebecca Kahn ◽  
Corey M. Peak ◽  
Juan Fernández-Gracia ◽  
Alexandra Hill ◽  
Amara Jambai ◽  
...  
Keyword(s):  
Sierra Leone ◽  
Incubation Period ◽  
Population Connectivity ◽  
Disease Spread ◽  
Long Distance ◽  
Spatial Spread ◽  
Transmission Parameters ◽  
Incubation Periods ◽  
Using Data ◽  
The Impact

Forecasting the spatiotemporal spread of infectious diseases during an outbreak is an important component of epidemic response. However, it remains challenging both methodologically and with respect to data requirements, as disease spread is influenced by numerous factors, including the pathogen’s underlying transmission parameters and epidemiological dynamics, social networks and population connectivity, and environmental conditions. Here, using data from Sierra Leone, we analyze the spatiotemporal dynamics of recent cholera and Ebola outbreaks and compare and contrast the spread of these two pathogens in the same population. We develop a simulation model of the spatial spread of an epidemic in order to examine the impact of a pathogen’s incubation period on the dynamics of spread and the predictability of outbreaks. We find that differences in the incubation period alone can determine the limits of predictability for diseases with different natural history, both empirically and in our simulations. Our results show that diseases with longer incubation periods, such as Ebola, where infected individuals can travel farther before becoming infectious, result in more long-distance sparking events and less predictable disease trajectories, as compared to the more predictable wave-like spread of diseases with shorter incubation periods, such as cholera.

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